Whether or not the Orthodox gives the specific title of "co-Redemptrix" to Mary is immaterial. There is little doubt that she is elevated to the "mother of God" status and an object of veneration (worship). This is a "poor" tradition.
I find the Jesus prayer far more in line with what I believe the apostles would pray than the basic prayer to Mary. In fact, I cannot imagine for one moment Paul, Peter, James or John asking Mary to pray to our Lord Jesus asking forgiveness for their sins. But I suppose I'll hear some "traditional" story written in 852AD to that effect.
I did not, as I pointed out in that post, believe that the fact that we Orthodox do not believe that the Theotokos is a co-Redeemer, think that this would make Orthodoxy suddenly palatable to you! :-)
At the risk of repeating things you doubtless know, the title of Theotokos (birthgiver of God) was confirmed by the 3rd Ecumenical Council. It is not a Mariological title, it is primarily a Christological doctrine. If Christ was fully God and fully man in one single person, not two (as Nestorius claimed), then Mary was and is the birthgiver of God.
She is also the "Mother of God" -- although we use this title infrequently in Orthodox prayers. To say otherwise is to deny either her genuine human motherhood of Christ, or to deny Christ's divine nature. This is all Christology -- St. Cyril and others detected in Nestorius' refusal to call Mary the Birthgiver of God (let alone Mother of God), an subtle but genuine underlying belief that somehow there were two persons in Christ -- a human person, and a divine person. The consequences for our salvation are obvious, since it would mean that God didn't *really* become man -- he just sort of cohabited a bodily space with a man.
You also have doubtless had explained to you the difference between veneration and worship. Even if you do not accept a difference, I can assure you that at least in Orthodoxy, that distinction is very acute, even in the most uneducated peasant.
Asking her to pray to God for the forgiveness of our sins is not a feature of Orthodox prayer that springs to mind, although it may be there. I'd have to check our liturgical texts. Our prayers to her are more of a supplicatory matter -- it's a rough world, and you ask as many people to pray for you as you can when you're getting through life.
Again, I don't expect any of this to make Orthodoxy palatable to you, but I write in the interest of clarification.
The disciples did ask Jesus how to pray and he responded by teaching them the Lord's Prayer. At no time did he tell them to run it by his mother first.
The council of Ephesus confirmed that status in 4 century AD after Nestorius questioned it. Whoever "elevated" her, did so before the 4 Century. My bet is on Archangel Gabriel.